Bose-Einstein condensation in inhomogeneous Josephson arrays

Abstract

We show that spatial Bose-Einstein condensation of non-interacting bosons\noccurs in dimension d < 2 over discrete structures with inhomogeneous topology\nand with no need of external confining potentials. Josephson junction arrays\nprovide a physical realization of this mechanism. The topological origin of the\nphenomenon may open the way to the engineering of quantum devices based on\nBose-Einstein condensation. The comb array, which embodies all the relevant\nfeatures of this effect, is studied in detail.\n